An Earth-friendly way to easily upgrade and fix your own computer

We’ve been in Taiwan for over a week: the new 1.7 Micro Desktop PCBs
arrived and are fine, the casework is underway (a cheap-and-cheerful
3D printer sourced), Laptop PCB1 can go for prototyping, and fun and
games with NAND Flash on the A20.

1.7 Micro Desktops Arrived

If you recall from the previous
update, these boards
have had to have a voltage-shifter added to the microSD card slot.
Works perfectly… with 3.3 V (or thereabouts) on one side and 3.3 V
(or thereabouts on the other) so for the purposes of stopping the
bun-fights on the current the TXS0108 does its job. However what
hasn’t been tested (because there isn’t yet a card which does 1.8 V
VREFTTL) is 1.8 V to 3.3 V. What this revision does is pave the way
for a future revision of the Micro Desktop which can support 1.8 V
microSD cards… even though a given EOMA68 Card may actually only
have 3.3 V output. Certainly the RK3288 has the ability to step down
to 1.8 V, but it requires that entire GPIO bank’s voltage domain to be
dropped to 1.8 V in order to support it. By having a level-shifter
and then adding a variable voltage supply on the microSD card side the
same end result is achieved.

One thing the new level-shifter did not solve: the segfaults in the
sunxi 3.4.104 kernel’s NAND driver. More on this later.

Micro Desktop Casework

So almost two years ago now, Joshua very kindly arranged for a
prototype set of casework, done in Portland, which you’ve seen on the
photos and videos, here. Now, behind the scenes I’d been contacted
last year after FOSDEM 2016 by Mark van den Borre, who has
laser-cutting equipment. He kindly offered to
help do the Micro Desktop casework (500 sets).

Now, being in SE Asia I figured a few weeks ago that it would be a lot
cheaper and a lot less hassle to get the laser-cutting done in China.
I told Mark this, and I could feel that he was very disappointed.
After thinking about it overnight I had an epiphany: this is a libre
project, therefore come what may you damn well support people who do
libre projects, and to hell with the cost and/or hassle. So I
contacted Mark again, told him that I’d be more than happy to use his
laser-cutting service, and invited him to join the list.

Now, I don’t want to go into details (you can find them if you like,
on-list), but the discussion surrounding the development of the
prototype casework didn’t go as I would have liked. Suffice to say
that I am getting somewhat sad and fed up with sticking to Software
Libre principles and ethics. I’m not going to abandon them, but it’s
not fun at times. Anyway, it turns out that because I am the one with
the working CAD software and access to the actual prototype units, I’m
going to have to be the one to do the casework design anyway.

I am extremely grateful to the people whose clear expertise in
materials pointed out that a stack of plywood an inch high will have
about 1.5 mm of variations in height due to changes in temperature and
humidity. Luckily that’s only in the vertical direction, so the
initial design has been abandoned in favour of sides that will slot
into holders. I’ve made the design of the holders and 3D-printed
them, and also sent off the first revision DXF files for
laser-cutting. A stack should arrive next week, for testing.

Now, if any of you remember the fiasco of the Vivaldi Spark Tablet (I
learned only quite recently that its leader had been going around
lying about what actually happened), the key lesson that I learned
from that mess is that it is absolutely essential to design the
Casework at the exact same time as the PCB, and not to finalise either
until they are both good… and one fits into the other. I took that
lesson on-board for the 15.6” Laptop casework and as a result have
PCBs that actually fit into the 3D-printed laptop casework.

The reason why I didn’t apply the same lesson here is because the
stack of plywood designed in Portland was absolutely fine… except
for that materials hiccup if it transitions from dry to humid
conditions. So I wasn’t expecting a redesign… and the 1.7 Micro
Desktop PCB is finalised. As a result, the case that can be designed
around it isn’t perfect, but it’s going to have to do as a first
version. The design’s source code is
online, it’s GPLv3
licensed, and it’s a cloneable git repository, so please contribute if
you can do better. The git repo also contains images from the current
design.

Laptop PCB1

The 15.6” Libre Laptop’s main PCB (PCB1) shares a similar circuit for
its microSD card with the Micro Desktop. Having got the
level-shifting done I have cut and pasted the circuit over and will be
sending it off for prototyping soon. Now, as previously mentioned
both on the list and in previous updates, the plan is to introduce a
new housing which utilises verbatim the exact same PCB as used in the
laptop.

With a Pass-through Card, this new housing will basically be a 15.6”
LCD monitor… one where you know that the hardware will not be hacked
in order to spoof on-screen dialog boxes that trick you into typing
your password, for example (many LCD monitors now run full-processors
that could potentially be hacked over their HDMI port). Popping out
the Pass-through Card and putting in a Computer Card you now have an
all-in-one desktop PC - one with three built-in USB ports and one USB
audio port.

The primary reason for considering doing this extra housing is to
reduce the cost of the components used in the 15.6” Laptop, as it is
literally the exact same PCB as in the 15.6” Laptop. Remember, there
are only 150 pledges for the Laptop, which puts it squarely into quite
expensive unit cost territory: most small-to-medium-sized China PCB
assembly houses won’t talk to you for anything less than 500 units,
and even that’s hardly worth the setup and teardown time for them.

So (thanks to Johnathon on-list), a review has taken place of PCB1,
and a tiny mains-only power board (PCB4) has been created: we’ll see
how it goes.

EOMA68-A20 NAND

I can’t quite get over how long it’s taken to track this combined
hardware-software-related problem down, and just have to remind myself
not to blow a fuse or lose my patience, but I am done with trying to
use TSSOP-48 NAND ICs on the EOMA68-A20 PCB. It’s explained in-depth
on the list, but basically it’s a combination of “Legacy” TSSOP-48
NAND ICs going out of fashion (in favour of eMMC), the fact that when
you bring up a totally different interface (the external microSD card
slot) the damn NAND IC gets corrupted (!!), and the complexity and
cost it’s adding to the PCB when there’s no clear benefit and a lot of
risk and cost instead… I’ve taken the decision to simply cut the
NAND IC entirely.

Now, if it was a BGA-169 NAND, it would be possible to just literally
drop an eMMC in its place without even changing the PCB design,
because the lines from the A20 to do eMMC or NAND are quite literally
exactly the same. But because it’s a TSSOP-48, that’s not possible.
It would therefore require yet another (risky) redesign.

So instead, by removing the NAND IC entirely, space on Layer 3 of the
PCB is freed up so the internal microSD card slot may be connected to
SDC2 (the pins that the NAND was connected to). This makes the
INTERNAL microSD the 2nd priority boot device and the EXTERNAL microSD
the 1st priority. That’s a much better arrangement that simply wasn’t
possible to do with the NAND IC in the way. It’s also cheaper and
ensures the card is completely unbrickable.

For those people who may think that this is much slower: I
demonstrated during the campaign that Class 10 microSD cards, which
are rated at 80 MB/s, can actually read and write at around 20 MB/s.
That’s about as fast as SATA HDDs from five or six years ago.

3D Printers

About six weeks ago I sourced a $300 3D printer from China, designed by
a company called AnyCubic. It’s not perfect by any means
(injection-molded parts which aren’t straight) but with a Melzi 2
instead of the unbelievably brain-dead use of “Polulu”
prototyping-sized stepper driver ICs being pushed beyond thermal
limits, it does pretty damn well. I’m pushing it to 200 mm/sec - four
times above its nominal rated speed of 50 mm/sec - and the quality of
the output is pretty damn good.

Now, I’ve since sourced a $150 3D printer which is an all-aluminium,
sturdy frame and will be getting one of these to try out. If it
works fine, I will get 10 of them. The reason is very simple: when I
first looked at the newly VC-funded company Mohou, they had a very low
cost per unit (in order to attract business). Since then, the
honeymoon is over, and the cost of single quantities is now really
surprisingly high. In addition to that, having experienced the
difference between the “Apollo” Series PLA from https://www.123-3d.nl/
(which is beyond rubbish, beginning to border on deceptive
marketing practices, and no longer being offered), their PETG (which in complete contrast to the
Apollo Series PLA is really good), and Faberdashery’s
staggeringly-high quality PLA, I simply cannot and will not risk
producing 150 laptops for people, only to have them completely fall
apart literally in their hands by having used sub-standard quality
materials.

Also, after having talked to friends who do 3D printing and they
also having had absolutely dreadful experiences with absolutely
every single supplier except Faberdashery, including filling rooms
with acrid toxic fumes, having the material literally crumble in their
hands, and in one case explode into a hair-ball tangled heap of
filament, I simply cannot be bothered to go looking for alternative
materials: I already know that they will be sub-standard.

Bottom line: I really do have to order 80-100kg of PLA from
Faberdashery and have it shipped over to Taiwan. I cannot reasonably
expect Mohou or any other 3D printing “network” company to use 3rd
party PLA… so that means I will have to do it myself. Hence
getting ten identical, low-cost, “good enough” 3D printers and setting up
my own batch processing. Bear in mind that it takes around 24-36
hours non-stop to print one full set of the laptop’s 35 casework
parts, so that means 150 DAYS of non-stop round-the-clock 3D
printing! This is the reason for wishing to get a batch of ten 3D
printers - it might be possible to get the entire casework sets done in
around six weeks of non-stop operation.

You probably noticed that, after considering the injection-molding
idea, I dropped it. It’s just not practical for such a small volume
of units. Not at 35 separate pieces requiring 35 separate molds to be
developed.

Schedule

Regarding delivery dates, the answer is always always going to be
“when things are ready to go into production” (not necessarily
“perfect”). For reasons explained in the previous update, the
project’s still not at the phase where a set schedule is possible to
declare. As explained above, the EOMA68-A20 needs to go through
another pre-production revision - estimated time to make and then test:
4-6 weeks. The EOMA68-A20 casework still needs to be done (a front
plate arranged). The new Micro Desktop casework, because of the
redesign explained above. needs to be tested and a means and method
of manufacturing the corners found (3D printed, injection-molded, all
need investigating) - estimated time of 6-8 weeks in parallel with the A20
Card. The Pass-through Card needs another revision based on the
hardware-level debugging done in January. It’s a huge list of tasks
that would normally be tackled by a team of five to eight engineers. I’m
getting through them as best I am able.

Micro Desktop Housing for Computer Card

This is a Micro Desktop base unit and power supply unit with a beautiful laser-cut stack of 3mm plywood panels that creates an aesthetically attractive tiny base unit for your Computer Cards. Excludes Computer Card, keyboard, mouse and VGA monitor.

Orders placed now ship Mar 31, 2019.

Free US Shipping / $12 Worldwide

$450

PIY Laptop Housing Kit for Computer Card

This Print-It-Yourself (PIY) kit includes all the parts, cabling and
boards (main, power, and controller, assembled and tested), and
battery, charger, keyboard, LCD, and CTP-LCD for trackpad that are
needed to build a complete Libre Laptop once you 3D print the
enclosure from the freely available GPLv3+ licensed plans. Excludes
Computer Card.

Orders placed now ship Apr 30, 2019.

Free US Shipping / $25 Worldwide

$500

PFY Laptop Housing Kit for Computer Card

This Printed-For-You (PFY) kit has everything needed to create a full
EOMA68 Laptop, including a 3D printed set of casework parts,
bamboo plywood panels, tested and assembled PCBs, cables, battery,
charger, keyboard, LCD, and CTP-LCD for trackpad. Available in a
variety of colors and materials. Excludes Computer Card.

Orders placed now ship May 31, 2019.

Free US Shipping / $25 Worldwide

Material / Color

$1,200

Completely Assembled Laptop + Computer Card

A meticulously hand-assembled and fully-tested laptop. Includes your choice of EOMA68-A20 Computer Card and 3D-printed casework.

For those people who would like the opportunity to meet the designers
and have them personally go over the project's development, history,
future direction and much more, a week's time can be made available to
meet with you personally, to do a hands-on workshop to help you (and
any number of additional attendees) through the process of putting
together your own fully-functioning laptop and even take you through
the process of building and installing the software. Also included
will be one Laptop with a Computer Card which will be assembled
on-site. You must provide travel, accommodation, tools and a suitable
workshop and presentation space. Contact us directly for details.

Orders placed now ship May 31, 2019.

Free Worldwide Shipping

Material / Color

$20

PCMCIA/EOMA68 Breakout Board

One PCMCIA/EOMA68 Breakout Board with one surface mount PCMCIA header, and tracks to some convenient 2.54-mm-spaced through-holes. Added by popular demand, for access, tinkering, development work, testing, etc.

Orders placed now ship Mar 31, 2019.

Free US Shipping / $10 Worldwide

$35

Pass-through Card

A simple card that takes in HDMI and USB and passes them on. Turns a Laptop Housing into a portable, battery-powered dock for your smartphone, USB-HDMI dongle computer, and tablet, or a second screen, keyboard, and mouse for your existing laptop or desktop PC.

Orders placed now ship Mar 31, 2019.

Free US Shipping / $10 Worldwide

$15

USB + HDMI Cable Set for Standalone Operation

Includes a Micro HDMI Type D cable and 3-way USB-OTG Host-Charger cable tested and known to work with EOMA68 Computer Cards. These are the cables you need to run a Computer Card as a standalone device without the need for a housing. Also useful with the Micro Desktop or Laptop Housing to add a second screen and extra USB port.